This project describes the establishment and validation of a murine orthotopic xenograft model using fresh human tumor samples that recapitulates the critical components of human pancreatic adenocarcinoma. The authors discuss the proven and theoretical advantages of the model as well as future translational implications.
Clinical, molecular and genetic validation of a murine orthotopic xenograft model of pancreatic adenocarcinoma using fresh human specimens.
Specimen part, Cell line
View SamplesDetailed analysis comparing hiPSC lines that were newly generated and compared them to already established hiPSC lines
Molecular analyses of human induced pluripotent stem cells and embryonic stem cells.
Specimen part, Cell line
View SamplesAlefacept treatment is highly effective in a select group patients with moderate-to-severe psoriasis, and is an ideal candidate to develop systems to predict who will respond to therapy. A clinical trial of 22 patients with moderate to severe psoriasis treated with alefacept (7.5mg weekly i.v. x12 weeks) was conducted in 2002-2003, as a mechanism of action study. Patients were classified as responders or non-responders to alefacept based on histological criteria. Microarray data from PBMCs of 16 of these patients was analyzed to generate a treatment response classifier. We used a discriminant analysis method that performs sample classification from gene expression data, via nearest shrunken centroid method''. A disease response classifier using 23 genes was created to accurately predict response to alefacept (12.3% error rate in favour of responders). This preliminary study may provide a useful tool to predict response of psoriatic patients with alefacept.
Personalized medicine in psoriasis: developing a genomic classifier to predict histological response to Alefacept.
Sex, Age, Specimen part, Subject
View SamplesIn adult skin, each hair follicle contains a reservoir of stem cells (the bulge), which can be mobilized to regenerate the new follicle with each hair cycle and to reepithelialize epidermis during wound repair. Here we report new methods that permit their clonal analyses and engraftment and demonstrate the two defining features of stem cells, namely self-renewal and multi-potency. We also show that, within the bulge, there are two distinct populations, one of which maintains basal lamina contact and temporally precedes the other, which is suprabasal and arises only after the start of the first postnatal hair cycle. This spatial distinction endows them with discrete transcriptional programs, but surprisingly, both populations are growth inhibited in the niche but can self-renew in vitro and make epidermis and hair when grafted. These findings suggest that the niche microenvironment imposes intrinsic stemness features without restricting the establishment of epithelial polarity and changes in gene expression.
Self-renewal, multipotency, and the existence of two cell populations within an epithelial stem cell niche.
Specimen part
View Samplesgene expression database and algorithm to define cell expression modules
Identifying gene expression modules that define human cell fates.
Specimen part
View SamplesThe success of TNF inhibitors for treatment of psoriasis and other inflammatory diseases was previously attributed to blockade of innate immunity. In a clinical trial using etanercept TNF blocking agent to treat psoriasis vulgaris, we used affymetrix gene arrays to analyze broad gene profiles in lesional skin at multiple timepoints during drug treatment (baseline, and weeks 1, 2, 4 and 12) compared to non-lesional skin. This analysis created a temporal model of TNF-dependent gene regulation that informs molecular mechanisms of TNF-mediated inflammation. We identified four gene clusters that were differentially down-modulated during etanercept treatment: the cluster down-regulated most rapidly contained mostly dendritic cell activation genes. Culturing human keratinocytes with TNF, IFNg and IL-17 generated a list of keratinocyte genes regulated by each cytokine. The IL-17 pathway genes were strongly down-modulated early, whereas IFNg pathway genes were not down-modulated until final disease resolution at week 12. Finally, we show that TNF blockade rapidly inhibits IL-12/IL-23 p40 subunit expression, and that p40 neutralization inhibits psoriatic dermal migr-mediated Th17 polarization. We hypothesize that etanercept inhibits myeloid dendritic cell production of IL-23, a Th17 survival cytokine, resulting in rapid downregulation of IL-17 pathway genes. This data links effects of TNF blockade on the innate immune system with the adaptive immune system.
Effective treatment of psoriasis with etanercept is linked to suppression of IL-17 signaling, not immediate response TNF genes.
Subject, Time
View SamplesMild vs. severe psoriasis vulgaris is often distinguished by the Psoriasis Area and Severity Index. It is widely assumed that severe psoriasis involves higher levels of skin inflammation, but comparative molecular profiles of mild vs. severe disease have not been previously performed. In this study, we used gene arrays to phenotype North American patients with mild psoriasis vs. severe psoriasis.
The Spectrum of Mild to Severe Psoriasis Vulgaris Is Defined by a Common Activation of IL-17 Pathway Genes, but with Key Differences in Immune Regulatory Genes.
Disease, Disease stage
View SamplesExpression profile of dermal fibroblasts reprogrammed to a pluripotent state
Generation of human induced pluripotent stem cells from dermal fibroblasts.
No sample metadata fields
View SamplesThe most immature progenitors in the murine thymus are early T lineage progenitors (ETP). These cells are the precursors of more mature thymocytes that ultimately leave the thymus and colonize peripheral lymphoid tissues. As part of our efforts to define age-related changes in ETP, we harvested them from mice of different ages and performed whole transcriptome profiling. This analysis revealed major differences in patterns of gene expression between young and old ETP, and we were particularly struck by the significantly reduced expression of the gene encoding high mobility group A 2 protein (Hmga2). Overall design: The experiment compares gene expression in young adult (4-6 week old) and old (72 week old) mouse Early T Lineage Progenitors (ETP)
The expansion of thymopoiesis in neonatal mice is dependent on expression of high mobility group a 2 protein (Hmga2).
No sample metadata fields
View SamplesThe balance between glycolytic and oxidative metabolism shifts during differentiation of human embryonic stem cells (hESCs) and during reprogramming of somatic cells into pluripotent stem cells. However the contribution of glycolytic metabolism to various stages of pluripotency is not well understood. Additionally, few tools have been developed that modulate pluripotent stem cell glycolytic metabolism to influence self-renewal or differentiation. Here we show that the degree of human pluripotency is associated with glycolytic rate, whereby naive hESCs exhibit higher glycolytic flux, increased MYC transcriptional activity, and elevated nuclear N-MYC levels relative to primed hESCs. Consistently, the inner cell mass of human blastocysts also exhibits increased MYC transcriptional activity relative to primed hESCs and elevated nuclear N-MYC levels. Expression of the lactate transporter, monocarboxylate transporter 1 (MCT1), is strongly associated with the pluripotent state, and reduction of glycolysis using a small molecule inhibitor towards MCT1 decreases self-renewal of nave hESCs and feeder-free cultured primed hESCs, but not that of primed hESCs grown in feeder-supported conditions. Lastly, reduction of glycolytic metabolism via MCT1 inhibition in feeder-free primed hESCs enhances neural lineage specification. These findings validate the association between glycolytic metabolism and pluripotency, reveal differences in the glucose metabolism of feeder- versus feeder-free cultured hESCs, and show that pharmacologic regulation of glycolysis can influence self-renewal and initial cell fate specification of human pluripotent stem cells.
Glycolytic Metabolism Plays a Functional Role in Regulating Human Pluripotent Stem Cell State.
Cell line, Treatment
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